docs: def check_deps(self):
  		"""Dependency checking phase is performed in this method.
  		"""
  		shutit_global.shutit_global_object.yield_to_draw()
  		cfg = self.cfg
  		self.log('PHASE: dependencies', level=logging.DEBUG)
  		self.pause_point('\nNow checking for dependencies between modules', print_input=False, level=3)
  		# Get modules we're going to build
  		to_build = [
  			self.shutit_map[module_id] for module_id in self.shutit_map
  			if module_id in cfg and cfg[module_id]['shutit.core.module.build']
  		]
  		# Add any deps we may need by extending to_build and altering cfg
  		for module in to_build:
  			self.resolve_dependencies(to_build, module)
  
  		# Dep checking
  		def err_checker(errs, triples):
  			"""Collate error information.
  			"""
  			new_triples = []
  			for err, triple in zip(errs, triples):
  				if not err:
  					new_triples.append(triple)
  					continue
  				found_errs.append(err)
  			return new_triples
  
  		found_errs = []
  		triples    = []
  		for depender in to_build:
  			for dependee_id in depender.depends_on:
  				triples.append((depender, self.shutit_map.get(dependee_id), dependee_id))
  
  		triples = err_checker([ self.check_dependee_exists(depender, dependee, dependee_id) for depender, dependee, dependee_id in triples ], triples)
  		triples = err_checker([ self.check_dependee_build(depender, dependee, dependee_id) for depender, dependee, dependee_id in triples ], triples)
  		triples = err_checker([ check_dependee_order(depender, dependee, dependee_id) for depender, dependee, dependee_id in triples ], triples)
  
  		if found_errs:
  			return [(err,) for err in found_errs]
  
  		self.log('Modules configured to be built (in order) are: ', level=logging.DEBUG)
  		for module_id in self.module_ids():
  			module = self.shutit_map[module_id]
  			if cfg[module_id]['shutit.core.module.build']:
  				self.log(module_id + '    ' + str(module.run_order), level=logging.DEBUG)
  		self.log('\n', level=logging.DEBUG)
  
  		return []